Installation
47
Operating Instructions HYGROPHIL® H 4230-10 Serie A BA 030520
3.6.2
Setting the ejector’s operating pressure
The gas to be measured is extracted from the respective system using the
ejector and pumped through the measuring unit. The ejector is operated with
compressed air.
The operating pressure of the compressed air must be set in line with the
pressure at the extraction point. The lower the pressure in the customer
system, the higher it is necessary to set the pressure.
Maximum efficiency of the ejector is obtained at a pressure of 5 bar. The
negative pressure in the customer system compared to the pressure in the
measurement station must not exceed 250 hPa.
Flow resistances occur in the hose and filter and these are intensified further
by dirt. For this reason, the maximum permissible negative pressure allowed
to be set is 200 hPa. This also provides leeway in terms of longer
maintenance intervals.
The air pressure should be at least 2 bar. This ensures that sufficient
reserves are available should the flow resistance be increased by dirt.
A maximum excess pressure of 5 hPa is permitted at the extraction point.
This can be influenced by choosing the extraction point well (e.g. extraction
before rather than after a blower).
In cases of excess pressure or a negative pressure of more than -200 hPa, it
is possible to check whether it would be permissible to run the unit’s outlet
back to the customer system. HYGROPHIL then works neutrally in terms of
pressure. Ask for advice if required. Also observe the output level (function
key F3). This should be between 60 and 70%, so that a sufficient control
range is available.
If you have installed HYGOPHIL properly, you can start up the equipment as
described in 4.1. Please note the following points with regard to
setting the
operating pressure
:
● Set the pressure at the compressed air conditioner’s reducing valve to a
minimum of 2 bar to begin with and start measuring.
The proportional valve adjusts the air flow rate to the correct value in line
with the pressure in the customer system and the flow relationships.
● If the value of 2 bar set for the pressure is not sufficient to generate the
nec
essary gas flow rate and the message „FLOW TOO LOW” is output,
increase the pressure to a maximum of 5 bar.
● About an hour after starting up the system, check again whether errors
are displayed and make any corrections that are necessary.
Also above the output level (function key F3). This should be between 60
and 70%, so that sufficient control range is available.
